The present invention relates to a method of and an arrangement for separating a liquid mixture of a solution by converting a part of the liquid mixture or a part of the solvent of the solution in vaporous phase and subsequent condensation of the thus produced vapor, whereby the liquid mixture or the solution is brought in contact with (micro) porous separating wall with pores through which only the vapor can pass, but the liquid mixture or the solution cannot pass.
Presumption for conducting of this known process was that the porous separating wall is not wettable by the liquid mixture of the solution, or in other words is lyophobous or hydrophobous, since the pentration of liquid into the pores of the porous separating wall or a passage of the liquid through the porous separating wall must be prevented under all conditions. On these grounds, the above described methods were not suitable for such liquid mixtures or solutions which wet the porous separating wall in some conditions of the method. Moreover, the known method was performed so that the vapor transport through the pores of the porous separating wall is hindered as little as possible or not hindered at all by gas available in the pores, in other words remaining and/or entrained gas.